The invention relates to a differential pressure threshold detector, having a control magnet and a reed switch actuated thereby, said switch having two contact reeds.
According to the position of the reed switch in relation to the control magnet, the reed switch on movement of the control magnet opens or closes an electric actuation circuit.
The function of the reed switch as actuation circuit opener or closer is determined generally by the assembling of the other electric monitor and regulator devices to which the differential pressure detector is connected. Thus in practice on one occasion the one function and on another the other is required. For the detector this signifies that according to need detectors must be equipped with different reed switches. Frequently the assembly of the electric monitor installation to which the detector is to be connected is not known, not yet known or not correctly known, with the consequence that detectors are available which are of the wrong kind and therefore are not usable. The reed switches cannot moreover be simply exchanged by the user of the detector, since they are an integral part of the entire detector. Thus in fact the entire detector must be replaced. Since as a rule the manufacturer and the user of the detector are not identical, such an exchange usually involves considerable expense.